Detecting bacteria contained in a specimen and determining the form thereof is being carried out in the fields of clinical examination, food sanitation examination, and the like.
An agar culture method is generally known for a method of detecting bacteria and determining the form thereof. This is an examination method of applying a sample to agar media, and classifying a colony, which is formed through culturing the bacteria over a predetermined time, using a microscope by an observer. However, in the agar culture method, the processing is complicated as it is a manual method, and it takes time to determine the form of the bacteria as culturing is required.
Thus, a method of detecting bacteria with a particle measurement device such as flow cytometer and determining the form thereof has been proposed in recent years.
For instance, U.S. Patent Publication No. 2004/0219627 discloses, as a method of determining the form of the bacteria contained in urine, a bacteria measurement method of creating a scattergram with information on the size of the bacteria and fluorescence information as parameters, analyzing the distribution state of the bacteria on the scattergram, calculating the tilt of a collection of particles from the distribution state of the particles of the entire scattergram, and determining whether the form of the bacteria in the specimen is a rod-shaped bacteria or a coccus based on the calculated tilt.
However, only the bacteria of a single form may not necessarily exist in the specimen, and the bacteria of different forms such as rod-shaped bacteria, chain coccus, and staphylococcal may exist in plurals. In such case, it is difficult to determine the form of the bacteria with the bacteria measurement method disclosed in U.S. Patent Publication No. 2004/0219627.